Mast Antennas

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Unplug antenna lead-in connector from radio receiver and plug a test antenna into radio. Make sure antenna base is grounded to the vehicle chassis and keep hands off the mast.

Check radio reception in an area away from electrical interferences. Tune to several weak and strong AM and FM stations. If the radio reception improved, the problem exists with the antenna and/or lead-in cable. If the reception is still poor, refer to Audio System Troubleshooting Hints.

Fig 1: Identifying Mast Antenna System Components

Courtesy of GENERAL MOTORS CORP.

Callout	Component Name
1	Negative Battery Cable
2	Coaxial Cable Conductor - Radio End
3	Coaxial Cable Metal Outer Shield - Radio End
4	Coaxial Cable Metal Outer Shield - Antenna End
5	Coaxial Cable Conductor - Antenna End
6	Antenna Base
7	Antenna Mast
8	Antenna Coaxial Cable

Radio Poor Reception

Ohmmeter Probes At Points	Resistance Measured In Ohms
1 and 3	Less than 0.2
1 and 4	Less than 0.2
1 and 6	Less than 0.2
1 and 2	Infinite
1 and 5	Infinite
1 and 7	Infinite
2 and 3	Infinite
2 and 4	Infinite
2and 6	Infinite
3 and 4	Less than 0.2
3and 6	Less than 0.2
3 and 5	Infinite
3 and 7	Infinite

Refer to the table when testing the antenna and/or lead-in cable.

Measure the resistance from the coax center conductor to antenna mast.
Total resistance from end to end of center conductor:
- RG-58/RG-59 type cable - less than 0.20 Ω
- RG-62/RG-62M type cable - less than 3.5 Ω
When checking the resistance, cautiously wiggle the lead-in tip and cable. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS .
Measure the resistance from the cable center conductor to metal case.
Replace the antenna and/or lead-in cable when the above readings are not obtained.